Which of the following is an example of a non-physiologic artifact?

Electrical interference is considered a non-physiologic artifact because it arises from external sources rather than the biological activity of the patient. This type of artifact does not originate from neural or muscular activity within the body but rather from various electrical devices or equipment in the operating room environment that can disrupt the monitoring signals. As a result, it can create misleading information in the neurophysiologic data being collected during intraoperative monitoring.

High levels of muscle tension are a physiologic phenomenon that can produce interference and noise in the signals being monitored, and thus they reflect actual physiological activity. The ECG signal is also a physiological measure and is an important diagnostic tool as it provides information about the heart's electrical activity. Slow signals due to perspiration may indicate changes in impedance or signal quality but are still related to the physiological state of the patient, making them physiologic artifacts. The distinction of electrical interference lies in its origin; it is unrelated to the body's internal physiological processes.